To clarify/follow up something I posted earlier regarding netplay:
Netplay is a bonus, not a miracle. Netplay did not revive a scene for old fighting games that were actually already good. I can name several good titles that had scenes that are dead now even with netplay support. It also didn't create a scene for the PC games that came equipped with it. Again, I can name several titles that are PC games with netplay that are now dead. The majority of popular games played at tournaments either don't have netplay or didn't until very recently. All netplay really does is let people play casuals when either: they live out in the middle of nowhere, or the scene is dead except for a handful of hardcore diehard fans, or allows people to play during the week when no local events are happening.
The real issue is indeed availability. Regardless of how good a game is; if it's not available as a console standard it isn't going to thrive outside of Japan. These days, especially with Evolution being a console tournament now, if a game thrived without a console release it'd be a miracle.
Between a console release versus a PC release, if the game didn't get a console release it would be as good as dead in terms of major tournaments, there's really hardly any question of that. It might still get played as a side event, but even that would be pushing it. On the flipside, if it did get a console release but didn't get a PC release then all you'd lose is just a handful players.
But, the community is really fickle. Even with arcade perfect ports some games just don't make it in the long run, so getting a console port isn't any sort of guarantee either.
It's also obvious that netplay can't be the core to a community either. It isn't an acceptable medium for serious tournaments, though you can have fun little "mock" tournaments online. Potential cheating/abuse like autofire and macros is enough reason in itself, but lag is also not acceptable for tournaments.
I still think there's a lot of power in netplay though. In my own experience there's been quite a few games that I never would have even tried if not for netplay, and I know I'm not the only one. Plus, the number of rounds and the number of different players I've played over netplay is significantly higher than the number I've played offline. I've learned things that I know I would have otherwise not learned. And I've even got to play some players from Japan. I am assuming these sorts of things are similar with other people.
I also still think it can "assist" in building a scene, though I don't think it'd be the deciding factor that could otherwise make or break a scene.